package com.hmdp.utils;

import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;

import java.util.Collections;
import java.util.UUID;
import java.util.concurrent.TimeUnit;


public class SimpleRedisLock implements ILock{

    private String name;
    private StringRedisTemplate stringRedisTemplate;

    public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.name = name;
        this.stringRedisTemplate = stringRedisTemplate;
    }

    private static final String KEY_PREFIX = "lock:";
    private static final String ID_PREFIX = UUID.randomUUID().toString();
    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT; // 初始化unLock.lua脚本
    static {
        UNLOCK_SCRIPT = new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unLock.lua"));
        UNLOCK_SCRIPT.setResultType(Long.class);
    }

    // 尝试获取锁
    public boolean tryLock(long timeOutSec) {
        // 获取当前线程的id
        String threadId = ID_PREFIX + Thread.currentThread().getId();
        // 获取锁
        Boolean isSuccess = stringRedisTemplate.opsForValue().setIfAbsent(KEY_PREFIX + name, threadId, timeOutSec, TimeUnit.SECONDS);
        return Boolean.TRUE.equals(isSuccess);
    }

    // 释放锁
    public void unLock(){
        // 获取当前线程的id
        String threadId = ID_PREFIX + Thread.currentThread().getId();
        // 调用Lua脚本
        stringRedisTemplate.execute(UNLOCK_SCRIPT, Collections.singletonList(KEY_PREFIX + name), threadId);
    }

    /*public void unLock() {
        // 获取当前线程的id
        String threadId = ID_PREFIX + Thread.currentThread().getId();
        // 获取锁中的id
        String id = stringRedisTemplate.opsForValue().get(KEY_PREFIX + name);
        // 判断是否一致
        if (threadId.equals(id)) {
            // 如果一致，才能进行释放锁
            stringRedisTemplate.delete(KEY_PREFIX + name);
        }
    }*/
}
